Strange message when launching Audacity

After downloading Audacity 2 for mac I always encounter a message where it says "Welcome to Unknown! ver 2.4.0 This is a trial version of Unknown which will expire in 14 days. Then it gives you the option to press Continue, Purchase or Authorize. I’m confused. Is this Audacity if not what is this software doing in Audacity and which one should I select? Thanks for the help.

No that’s not Audacity. Audacity does not have such a message and Audacity does not expire.

Are you able to run Audacity?
Are you sure that it is Audacity 2.0 (look in the “Help menu > About Audacity”).
Did you download Audacity from here:

Yes I’m sure it’s Audacity and that’s where I downloaded it using .dmg for mac. If I click continue it will show the Audacity screen so I’m just puzzle as to where it came from. Here’s a screen shot.
Screen Shot 2012-04-15 at 11.58.20 PM.png

The message seems to be generated by a plugin called “BIAS SoundSoap” (noise reducer), that comes together with the Roxio “Toast” CD burning software. See the Roxio forum: Since Installing Toast 11 receive ‘Welcome to Unknown’ notice when I open Audacity…

Thanks. That clears up the mystery. So I guess I can just remove this plugin so it won’t show up next time right?

Yes, remove it from wherever it was installed.